Effect of Pressure on Structure and NOX Formation in CO-Air Diffusion Flames.
Abstract
A study has been made of flame structure and nitric oxide formation in confined laminar CO-air diffusion flames over a pressure range from 1 to 50 atm. The shape of the flames changed from wide and convex at 1 atm to slender and concave at 50 atm, with the greatest change occurring below about 10 atm. Flame height decreased with increasing pressure from 1 atm to about 10 atm, but was independent of pressure at higher pressures. The regimes of stable burning decreased with increasing pressure up to 50 atm, with the greatest reduction occurring between 1 atm and 20 atm. The molar emission index (the moles of nitrogen oxides formed per mole of carbon monoxide consumed) increased as the pressure was increased above 1 atm, reached a maximum at approximately 28 to 30 atm, and thereafter decreased slowly up to 50 atm. Circumstantial evidence is offered to support the proposition that the concentrations of nitrogen oxides in the flames approach their equilibrium values for pressures above about 20 atm. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1979
- Accession Number
- ADA078612
Entities
People
- Howard G. Maahs
- Irvin M. Miller
Organizations
- National Aeronautics and Space Administration